fix(core): previous core version broke column resize, closes #207

Author: Ghislain Beaulac

package.json

@@ -83,7 +83,7 @@
     "lodash.isequal": "^4.5.0",
     "moment-mini": "^2.22.1",
     "rxjs": "^6.3.3",
-    "slickgrid": "github:6pac/SlickGrid",
+    "slickgrid": "^2.4.9",
     "text-encoding-utf-8": "^1.0.2",
     "tslib": "^1.9.3",
     "vinyl-paths": "^2.1.0"